/Engine/Plugins/Experimental/MeshModelingToolsetExp/Source/MeshModelingToolsExp/Public/MeshSelectionTool.h
Grow the active triangle selection to include any triangles touching a vertex on the selection boundary
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(CallInEditor, Category=SelectionEdits, Meta=(DisplayPriority=3)) void Grow()